Ovarian cysts are fluid-filled sacs in your ovaries, and it’s possible to have one without even realizing it. But it’s also possible that one will make like a tiny volcano and basically erupt, which can sometimes—but not always—cause a lot of pain. Here’s what you should do if you have a hunch you’ve got a ruptured ovarian cyst.

First, you should know that not all ovarian cysts are created equal.

Like basically anything else in your body, ovarian cysts can come in a lot of forms. Doctors put most ovarian cysts into two categories: follicular cysts and corpus luteum cysts.

Follicles are little sacs on your ovaries that grow and hold an egg, which is released when the follicle breaks open, according to the U.S. Department of Health and Human Services. This is a normal part of your menstrual cycle. But a follicular cyst can form if the follicle doesn’t break open when it’s supposed to. Most women who have a follicular cyst don’t know it, and the cyst will typically go away within one to three months.

The other main kind of ovarian cyst is a corpus luteum cyst. After your follicle releases an egg, the empty sac shrinks and becomes a mass of cells called corpus luteum. Those cells then make estrogen and progesterone to prepare another egg for your next menstrual cycle. Sometimes, though, the sac doesn’t shrink like it’s supposed to and can become filled with fluid or blood, creating a corpus luteum cyst, Melissa Goist, M.D., an ob/gyn at the Ohio State University Wexner Medical Center, tells SELF. This kind of cyst usually goes away in a few weeks, but it can sometimes keep growing and become almost four inches wide, according to the U.S. Department of Health and Human Services.

There are other less-common, non-cancerous cysts you can develop too. Those include endometriomas, which can form as a result of endometriosis; dermoids, which are cysts that can have hair, bones, teeth, or skin (yes, we know this is pure nightmare fuel); and cystadenomas, which show up on the surface of the ovary and can be filled with a watery or mucus-based fluid, according to the Mayo Clinic.

While it’s possible to have a cancerous cyst, most cysts are completely harmless. This is why, if doctors discover you have an ovarian cyst during an exam, they may recommend just waiting for a few months to see if it goes away, according to the Mayo Clinic.

Ovarian cysts don’t always cause trouble, but they can if they rupture or don’t stop growing.

Most cysts are small and don’t cause symptoms, according to the U.S. Department of Health and Human Services. But if they grow large enough, they can cause pain in your lower abdomen on the side of the cyst, along with bloating or a sense of pressure.

Dermoid cysts and cystadenomas in particular can become pretty large, the Mayo Clinic says, which, in addition to causing those symptoms, can cause the ovary to shift from its usual position, increasing the chances it will twist on itself in a painful issue known as an ovarian torsion. This can lead to nausea and vomiting, along with pain.

And if your ovarian cyst actually bursts, as it releases fluid into your body, the pain can definitely make you take notice. Although your body usually just reabsorbs the fluid without you realizing anything happened, sometimes it can irritate the lining of your abdomen, Stephanie V. Blank, M.D., director of women’s health at Mount Sinai Downtown Chelsea and professor of obstetrics, gynecology and reproductive science at Icahn School of Medicine at Mount Sinai, tells SELF.

The pain you feel may depend on a cyst’s size. You might have a sudden, severe, sharp, stabbing feeling when a larger cyst bursts, Lauren Streicher, M.D., an associate professor of clinical obstetrics and gynecology at Northwestern University Feinberg School of Medicine, tells SELF. With a smaller cyst, you might feel a dull ache come on that becomes more intense as the fluid makes its way into your body. The pain may also come and go.

If your cyst was filled with blood or was very large when it burst, you may experience internal or vaginal bleeding, which in addition to severe abdominal pain can lead to symptoms like fever, vomiting, dizziness, weakness, and rapid breathing, according to the U.S. Department of Health and Human Services.

If you’re in pain from what you think is a burst ovarian cyst, you may or may not need medical attention.

If you experience a sharp, sudden abdominal pain that goes away quickly and isn’t accompanied by any other symptoms, it may have been a burst ovarian cyst or even just regular [ovulation pain], known as mittelschmerz. If pain relievers help and that was your only symptom, you don’t need to seek treatment unless you’re actually worried, Dr. Streicher says.

If your midsection pain doesn’t go away even after pain relievers or comes along with symptoms like nausea, vomiting, dizziness, and vaginal bleeding, you need to call a doctor. Depending on the level of pain you’re in, your doctor may have you come into the office or head to the emergency room. Since the symptoms of an ovarian cyst can be similar to serious complications of conditions like appendicitis, it’s important to get severe symptoms checked out ASAP, Dr. Streicher says.

Doctors may do a pelvic exam, lab tests, or a transvaginal ultrasound, i.e., an ultrasound with a wand that goes inside your vagina, to try to see what’s going on. If you had a cyst that burst, your doctor will usually be able to see some fluid or blood in your pelvis.

The first line of treatment is about managing your pain. Taking an NSAID like aspirin or ibuprofen can help, Dr. Streicher says, but in more extreme cases you might get IV pain medication at the hospital. Your doctor may also recommend you go on hormonal birth control to prevent ovulation and reduce your chances of a cyst recurring.

In rare cases, you may need surgery to remove an ovarian cyst. Doctors may be able to just excise the cyst, but in extreme situations, a cyst may require removing the affected ovary, according to the Mayo Clinic.

If you’re in real pain that won’t go away and think you had an ovarian cyst burst, don’t try to ride it out; call your doctor. She can take a quick look inside you to see what’s going on and help you understand what happened, plus when you should start to feel better.